Region
Developing countries
4
United States --
4
Developing countries --
3
Europe --
2
European Economic Community countries --
2
Japan --
2
United States
2
21st century
1
Britain
1
Europe
1
Former Soviet republics --
1
Great Britain
1
Great Britain --
1
India --
1
Japan
1
Japan - --
1
Malaysia
1
Soviet Union
1
United States - --
1